A temperature measuring method of a component of a substrate processing chamber including a surface being worn or being deposited with a foreign material by using. The method includes: providing data representing a relationship between a temperature of the component and an optical path length of a predetermined path within the component; measuring an optical path length of the predetermined path within the component by using optical interference of reflection lights of a low-coherence light from the component when the low-coherence light is irradiated onto the component to travel through the predetermined path; and obtaining a temperature of the component by comparing the measured optical path length with the data.

A method is provided for determining the thickness of a retina. A single beam is used to illuminate the retina of a patient. Interference between reflections off different layers within the retina cause autocorrelation in the returned signal. A spectrometer produces a frequency spectrum of the beam reflected by the retina, and an FFT applied to the frequency spectrum produces a spatial domain signal (SDS). Autocorrelation within the reflected beam results in edges within the spatial domain signal, and the spatial coordinate of the SDS at which the power of the SDS drops precipitously indicates the distance between the nerve fiber layer (NFL) and the layers between the inner segment/outer segment (IS/OS) and the retinal pigment epithelium (RPE), the dominant scatterers. By analyzing autocorrelation, a single beam can be used. This avoids the problem of movement of the patient, arising in the use of a standard OCT interferometer, resulting in a simpler and less expensive technique of measuring retinal thickness.

The system includes a dual interferometer sub-system configured to measure flatness across a substrate. The system includes a mass sensor configured to measure the mass of the substrate. The system includes a controller communicatively coupled to the dual interferometer sub-system and the mass sensor. The controller includes one or more processors. The one or more processor are configured to execute a set of program instructions stored in memory, the set of program instructions configured to cause the one or more processors to determine a thickness distribution of at least one of the substrate or a film deposited on the substrate as a function of position across the substrate based on one or more flatness measurements from the dual interferometer sub-system and one or more mass measurements from the mass sensor.

The invention relates to a measuring device (10) and a method for determining a length measurand of a workpiece. A carrier part (13), on which a probe unit (18) is arranged immovably in a first spatial direction (x), can be moved or positioned by means of a positioning arrangement (12). At least one laser interferometer (24) is connected to the carrier part (13) immovably in the first spatial direction (x). By means of a first laser measuring beam (L1) and a second laser measuring beam (L2), the laser interferometer (24) generates a first measurement signal (S1), which measurement signal describes the distance of the laser interferometer (24) from a first reflector (25) in the first spatial direction (x), and a second measurement signal (S2), which describes the distance of the laser interferometer (24) from a second reflector (26) in the first spatial direction (x). A probe system plane (E), which is immovable in the first spatial direction (x) relative to the carrier part (13) or the probe unit (18) and which extends at right angles to this first spatial direction (x), therefore has a position in the first spatial direction (x) that can be determined by means of the distances of the laser interferometer (24) from the first reflector (25) and the second reflector (26).

The determination of in-plane distortions of a substrate includes measuring one or more out-of-plane distortions of the substrate in an unchucked state, determining an effective film stress of a film on the substrate in the unchucked state based on the measured out-of-plane distortions of the substrate in the unchucked state, determining in-plane distortions of the substrate in a chucked state based on the effective film stress of the film on the substrate in the unchucked state and adjusting at least one of a process tool or an overlay tool based on at least one of the measured out-of-plane distortions or the determined in-plane distortions.

An apparatus and method of measuring biofilm and biological activity on a surface is disclosed. The apparatus includes a biofilm, which includes one or more microorganisms, grown on a substrate. A viewing window is placed on a surface of the biofilm and a gas bubble is introduced between the viewing window and the surface of the biofilm. The space between the substrate and the viewing window may be enclosed in a casing that has an inlet and an outlet, forming a flow cell. A microscope system, such as a white light interferometer, captures data of the biofilm in situ and non-destructively. The 3D images of biofilm surface have high resolution while maintaining a large field of view. The apparatuses and methods will be useful for fundamental studies of biofilms, biomedical and environmental screening, and many other applications in biology and the life sciences.

A laser measurement system for measuring up to 21 geometric errors, in which a six-degree-of-freedom geometric error simultaneous measurement unit and a beam-turning unit are mounted on either the clamping workpiece or the clamping tool, while an error-sensitive unit is mounted on the remaining one, the beam-turning unit has several switchable working postures and multi-component combinations in its installation state, it can split or turn the laser beam from the six-degree-of-freedom geometric error simultaneous measurement unit to the X, Y, and Z directions in a proper order, or the beam-turning unit can split or turn a beam from the error-sensitive unit to the six-degree-of-freedom geometric error simultaneous measurement unit. The present invention is of simple configuration and convenient operation. Up to 21 geometric errors of three mutual perpendicular linear motion guides are obtained by a single installation and step-by-step measurement.

A testing device for testing an inner surface of a rotationally symmetrical cavity in a workpiece has a measuring head which defines an axial direction, and on which an optical system is situated. The optical system is in image transmission connection with an image recorder and a downstream evaluation apparatus. The testing device also has an illumination arrangement for illuminating an imaging area of the inner surface which is detected by the optical system. The illumination arrangement is designed and configured for illuminating the inner surface which is detected by the optical system. The illumination arrangement can illuminate the inner surface to be tested from different illumination directions in order to generate shadow images of the topography of the inner surface. The evaluation apparatus is designed and configured for determining the topography based on the shadow images recorded by the image recorder.

A measurement method and system include illuminating an object to be measured with light at two different wavelengths and an incident angle; capturing an image of the object; detecting a frequency of an interference pattern from the image using Fractional Bi-Spectrum Analysis; and calculating a thickness of the object based on the Fractional Bi-Spectrum Analysis. The thickness is calculated based on a relationship between the thickness and the frequency of the interference pattern. The Fractional Bi-Spectrum Analysis is performed on a linear medium with the two different wavelengths being known.

A temperature measuring method of a component of a substrate processing chamber including a surface being worn or being deposited with a foreign material by using. The method includes: providing data representing a relationship between a temperature of the component and an optical path length of a predetermined path within the component; measuring an optical path length of the predetermined path within the component by using optical interference of reflection lights of a low-coherence light from the component when the low-coherence light is irradiated onto the component to travel through the predetermined path; and obtaining a temperature of the component by comparing the measured optical path length with the data.